12011222221 has 2 divisors, whose sum is σ = 12011222222. Its totient is φ = 12011222220.

The previous prime is 12011222137. The next prime is 12011222227. The reversal of 12011222221 is 12222211021.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11419273321 + 591948900 = 106861^2 + 24330^2 .

It is a cyclic number.

It is not a de Polignac number, because 12011222221 - 2²⁵ = 11977667789 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 12011222195 and 12011222204.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12011222227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6005611110 + 6005611111.

It is an arithmetic number, because the mean of its divisors is an integer number (6005611111).

Almost surely, 2^12011222221 is an apocalyptic number.

It is an amenable number.

12011222221 is a deficient number, since it is larger than the sum of its proper divisors (1).

12011222221 is an equidigital number, since it uses as much as digits as its factorization.

12011222221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 12011222221 its reverse (12222211021), we get a palindrome (24233433242).

The spelling of 12011222221 in words is "twelve billion, eleven million, two hundred twenty-two thousand, two hundred twenty-one".